Access parent's function from child widget

[el33t]

I want to access a function in my parent from a child widget.

This is the code of the parent widget:

mainwindow.cpp

#include <QtGui>
#include <iostream>
#include "mainwindow.h"
#include "menu1.h"
 
 
 
mainwindow::mainwindow()
{
    men = new menu1(this); // This is the child widget 
 
    qs = new QStackedWidget(this);
    qs->addWidget(men);
    qs->setCurrentIndex(0);
}
 
mainwindow::functions1()
{
   std::cout<<"function called";
}

#include <QtGui>
#include <iostream>
#include "mainwindow.h"
#include "menu1.h"



mainwindow::mainwindow()
{
    men = new menu1(this); // This is the child widget 
    
    qs = new QStackedWidget(this);
    qs->addWidget(men);
    qs->setCurrentIndex(0);
}
 
mainwindow::functions1()
{
   std::cout<<"function called";
}

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Here is the code of the child widget.

menu1.cpp

menu1::menu1(QWidget *parent) :
    QWidget(parent)
{
 
   resize(880,558);
 
}

menu1::menu1(QWidget *parent) :
    QWidget(parent)
{

   resize(880,558);

}

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Now, I want to access funtion1 from 'men'. How do I do it?

I tried the following in men.cpp but got errors:

1) parent->funtion1();

This gives the error: 'class Qwidget' has no member named 'funtion1'

2) parent->parent->funtion1();

This gave the error : invalid use of member (did you forget the '&')
base operand of '->' is not a pointer


Any help would be appreciated.

Regards,

[wysota]

Either cast the parent pointer to the right type or store the pointer to the parent somewhere in the child when receiving it in the constructor. Or use signals and slots.

[el33t]

Either cast the parent pointer to the right type or store the pointer to the parent somewhere in the child when receiving it in the constructor. Or use signals and slots.

Ok, I'll try the casting.

But why is 'parent()' not working? Isin't it doing the same thing (pass the parent pointer) ?

[conner686]

Ok, I'll try the casting.

But why is 'parent()' not working? Isin't it doing the same thing (pass the parent pointer) ?

The return value of `parent()` is `QObject*` by default, not `mainwindow*`. As such, you do not have access to `mainwindow` functions, even though you're pretty sure that's what type of object you actually have. That's why the cast is neccessary; it tells the compiler that even though you have a `QObject*`, it should be treated as a `mainwindow*` and let you call those functions as normal.

[el33t]

Did the casting an everything worked like a charm. Thanks a lot for the assitance guys!